Design Of Small Off-grid Type Vertical Axis Wind Power Control System

With the depletion of non-renewable energy, the environment is getting worse and worse, economy and technology rapid development factors driving,the development of renewable energy technology has a huge space for development, which is particularly prominent in the development of wind energy.In our country, off grid small wind power technology is the main way to solve the problems of remote areas, such as plateau,island, pastoral areas and special environment.However, due to the seasonal variation of natural wind and load fluctuation, the application of the off grid small wind power generation system is limited and can not be widely used.In this paper, a small vertical axis wind turbine as the research object, the start wind speed is low, can be applied to more environment.In this paper, we mainly study and study the problem of maximum power point tracking(MPPT) control and battery charging and discharging control in the off grid wind power system. Study and analysis of existing wind power system maximum power point tracking methods, such as: tip speed ratio control, power signal feedback control and disturbance observation method of the control strategy.The maximum power control is determined by the variable step size duty ratio perturbation method which is suitable for the wind power system.The method improved shortcomings which is that perturbation and observation method perturbation variable size selection is unreasonable, resulting in system conversion efficiency is low, easy disturbance. the charging method combined with the phased charging method and MPPT to improve the charging efficiency of the battery, while ensuring the stability of the battery charging, prolong the service life of the battery.Through simulation analysis in the Matlab/Simulink environment, verify the maximum power tracking control method and the design of the battery charging strategy feasibility.Finally, the experimental results are obtained that Off grid type vertical axis small wind power control system which are designed with MPPT and battery charge and discharge control strategy in this paper, can be better to complete the design of function and improve the reliability and stability of small wind power system.